The object of this research project is to apply amniocentesis, cell culture and somatic cell hybridization techniques to antenatal detection of sickle cell anemia. Amniotic cells will be obtained at 14 - 16 weeks of gestation via transabdominal amniocentesis from fetuses at risk for sickle cell anemia. These cells will be propagated in cell culture. Bone marrow cells, obtained by aspiration or from surgical biopsy specimens from normal individuals and those with sickle cell anemia, will be cultured in the presence of erythropoietin which can stimulate synthesis of hemoglobin in vitro. Fetal and bone marrow cells will be fused in culture with inactivated Sendai virus. Hybrid mononuclear cells and heterokaryons, which do not multiply, will be isolated and cultured in the presence of erythropoietin for hemoglobin synthesis. The phenotype of the hemoglobin isolated by chromatographic techniques from the cell hybrid lines and the heterokaryon populations will be identified by starch gel and acrylamide gel electrophoresis, and two dimensional electrophoresis and chromatography (fingerprint). The phenotype of the amniotic fetal cell being tested by participating in hybridization will be inferred from the phenotype of the adult bone marrow cell line used and from the hemoglobin type isolated from hybrids or heterokaryons. If the bone marrow phenotype is hemoglobin S and the hybrid cell synthesizes only hemoglobin S, then the fetal genotype must be HbS /HbS which predicts that the fetus will develop sickle cell anemia. The development of a technique for detecting such fetuses in gestation permits the use of therapeutic selective abortion to prevent sickle cell anemia.